| abstract |
The present invention provides a lubricant composition for an internal combustion engine comprising a base oil of lubricating viscosity, wherein the base oil comprises an ether base stock of formula (A): where: Ra and Rb are aliphatic hydrocarbyl groups and may be the same or different; wherein at least one of Ra and Rb is branched-chain alkyl, alkoxy-substituted-alkyl or cycloalkyl-substituted-alkyl; the lubricant composition further comprising at least one aminic anti-oxidant and/or at least one phenolic anti-oxidant; and wherein the total combined amount of aminic and phenolic anti-oxidant in the lubricant composition is not more than 4.0 % by weight of the lubricant composition. In some embodiments, the ether base stock has the formula (1): where: R1, R2, R3, R4, R5 and R6 are as defined herein. The lubricant composition may be used for lubricating a surface in an internal combustion engine as well as for improving the fuel economy performance and/or piston cleanliness performance of an engine and/or a vehicle, such as an automotive vehicle associated with an internal combustion engine. |